Total Knee Replacement
Total knee replacement is an operation where the damaged parts of the knee (usually from osteoarthritis) are removed and replaced with metal and plastic components. It is significant surgery but can improve knee pain considerably once you have recovered.
When is a knee replacement necessary
There is no test you can do to determine when it is the right time for a knee replacement. It is important to consider how much your symptoms are impacting you, including pain and functional limitations, but also to take into account the recovery from surgery and the risks involved. You would often consider having a knee replacement if your knee pain affects your sleep, stops you from doing simple activities (such as walking) and non-operative measures have failed to control your pain.
All these things go into making the decision about whether having a total knee replacement is likely to be “worth it”. Dr Brooker will have a comprehensive discussion with you to help you make an informed decision about the timing of total knee replacement or other treatments.
The technical aspects
After your anaesthetic, often a spinal anaesthetic (needle in your back to numb your legs), Dr Brooker prepares your knee and leg with a sterile wash and makes a cut down the middle of your knee. Dr Brooker uses a subvastus approach to access the knee joint, which is a muscle sparing approach that improves pain and function in the early recovery period.
Using computer assisted robotic surgery Dr Brooker then assesses your knee and the damaged areas and decides on a specific surgical plan.
The damaged bone is removed with the aid of robotic equipment and the metal implants are inserted, usually with special bone cement. The robotic equipment increases the precision of the surgery and allows for less damage to the soft tissues.
At the end of the procedure the wounds are closed, usually with dissolvable sutures, and you will be moved to the recovery area of the operating theatre.
Recovery expectations
The recovery from a total knee replacement is usually painful and difficult, particularly in the first six weeks. Everybody has a different experience after knee surgery, but recovery typically involves:
- Walking with a walker or crutches begins the day after surgery
- Early movement (range of motion exercises) which are essential for preventing stiffness
- Driving is restricted for at least six weeks
- Pain and swelling are normal for several months
- Discomfort at three to four months is expected
- Return to normal activities typically occurs within three to six months
- Maximum strength and endurance may take up to one year
Post operative pain management
Severe pain is expected after a total knee replacement. It is managed with strong medications, ice, and moderating activity as required. In the initial weeks after surgery, when the pain and swelling are worst, it is still critical to do your range of motion exercises to prevent permanent stiffness. The other exercises and activities are not so important early on, and Dr Brooker advises prioritising the movement exercises and only completing the other exercises if your pain allows. This means that you will still be able to do the most important exercises but not overload your knee with pain and swelling.
Realistic outcomes
A knee replacement provides a functional prosthetic joint with significant pain relief and improved mobility, but it never feels like a completely normal knee. Once you have recovered from the surgery, low-impact activities such as walking, swimming, cycling, and gardening are typically well-tolerated. Higher impact activities like running or jumping sports may not be comfortable to do, and are not recommended as they accelerate implant wear.
Every patient has a different outcome with knee replacement surgery but a total knee replacement never feels like a normal knee. Common limitations include not being able to kneel on your knee replacement, an area of numbness around the scar (which can be permanent), mild stiffness which doesn’t affect function too much but can be a bit annoying, and sometimes ongoing pain, particularly with uneven ground or walking on sand for example. Usually your pain and function are much better after your knee replacement than before surgery but a knee replacement never feels completely normal.
Modern knee implants typically last 15-20 years or more. Younger, more active patients have a higher probability of requiring revision surgery in the future and generally don’t like their knee replacement as much as older patients. This is considered when determining surgical timing.
Making the decision
The decision to proceed with knee replacement requires careful consideration. Dr Brooker will provide comprehensive information regarding the likely outcomes and recovery process to assist with decision-making. Dr Brooker recommends talking to people you know who have had knee replacements to get an idea of the likely recovery (remembering that every patient is different) and the long term results. If knee pain significantly limits function despite conservative treatments, consultation regarding possible knee replacement surgery is appropriate.
Before your knee replacement:
Prior to having a knee replacement, maximising knee function and general health are important to increase your chance of having a good result. Gentle, no, or low impact exercise, such as swimming, walking in the pool or cycling, helps to improve muscle strength and knee motion without overloading the joint and creating inflammation and pain.
We know from scientific studies that being significantly overweight, having poorly controlled diabetes and cigarette smoking are risk factors for post operative infection after knee replacement surgery. Talk to your local doctor prior to considering joint replacement surgery to make sure your health is maximised with weight loss, tight diabetic control and cessation of cigarette smoking if required.
